1. Field of the Invention
This invention relates to an apparatus and a process for creating integral photography three-dimensional images, and more particularly, to a computer integrated process and optically improved and expanded apparatuses for creating integral photography three-dimensional images.
2. Description of the Related Art
A variety of systems for forming and viewing 3D images are known and can be grouped in the following groups: stereography, lenticular sheet imaging, auto-stereography, volumetric displays with fast rotating components, holotron technology, laser holography, and integral photography.
Stereography is often used in, for example, 3D cinema with shutter or polarised glasses. Lenticular sheet imaging is often used, for example, on flipping postcards. Auto-stereography includes eye tracking mechanisms adjusting lenticular sheets in front of LCD monitors. Other auto-stereography apparatuses use of lenticular sheets a diaphragm with numerous slit apertures instead of lenticular sheets. Holotron technology shows multiple perspectives in high frequency on a monitor. Laser holography is commonly used on credit cards.
The present invention relates integral photography, which has no popular application example today.
The integral photography is a concept to record a three dimensional scene on a photographic plate or wall. The plate consists of a multitude of individual lenses, placed beside and on top of each other. Every lens, with the photo layer behind it, functions as a miniature camera for recording the surrounding scene on the photo layer, as well as a miniature projector for projecting the recorded image on the photo layer out again into the surrounding. The spectator, looking on the ready picture wall, is looking into millions of small projectors, each projecting its 2D image directly into the spectator's eyes. The multitude of dots flowing into each other, when distantly observed, will turn into the previously recorded 3D image scene in the spectator's mind. The integral photography concept has not delivered any commercial use because a number of conceptual problems prevented the creation of satisfactory images.
The principle of integral photography includes the placement of many small lenses on top and beside of each other on a grid, each one recording and projecting a 2D image of the surrounding scene. When looking onto the grid of many lenses from a certain distance, the 3D image can be seen from any perspective within a certain range. The many small lenses on the grid are also referred here as the lens wall or picture wall
The principle of integral photography has been known since the beginning of the 20th century, but was never developed to a successful product because the proposed processes and apparatuses failed to deliver satisfactory images.
Past integral photography systems result in the following problems.
Prior art integral photography systems had to expose one complete lens wall with the original source in one shot, creating a pseudoscopic image. Pseudoscopic can be defined as reversed perspective, i.e., everything that should stick out actually sticks in. Only the exposure of a second lens wall with the pseudoscopic virtual image of the first lens created the normal perspective image. This two step process considerably reduces the image quality. Some prior art integral photography systems uses two lens walls behind each other with the imaging layer in between to integrate the two steps in one. The normal perspective image can be seen from the backside.
Prior art integral photography systems have problems correcting the following errors or achieving this features: uneven patterns in the backlit system; uneven patterns in the photo layer; uneven light towards the corners within a single lens; overlapping images on the image photo plane; and color intensity corrections; movement inside the image.
The individual exposure from an LCD monitor creates another new error source in that the distortion caused by the projection lens system between the LCD monitor and the individual lens during the exposure process must be corrected.
Prior art integral photography systems have severe problems with the planes being in focus. In fact, this issue is seen in the prior art as a paradox to the integral photography concept. On the one hand, the integral photography is intended to display objects in different distances to the observer. On the other hand, the small lenses on the lens wall can only be focused on one plane, either infinity or some closer plane, when recording the image. The resulting image can only be in focus in the single plane, making the whole approach useless. It was actually this paradox that inhibited the development of integral photography.
Most prior art systems only create poor image quality, with the photo layer being flat at the back of the lenses. U.S. Pat. No. 3,706,486 to Roger de Montebello shows two lens arrangement aspects necessary to obtain reasonable image resolutions. The photo layer at the back of the lens is spherical and in the center between front lens and photo layer was the diaphragm.